// Aqua background
CellStyle style = wb.createCellStyle();
style.setFillBackgroundColor(IndexedColors.AQUA.getIndex());
style.setFillPattern(CellStyle.BIG_SPOTS);
Cell cell = row.createCell((short) 1);
cell.setCellValue("X");
cell.setCellStyle(style);

// Orange "foreground", foreground being the fill foreground not the font color.
style = wb.createCellStyle();
style.setFillForegroundColor(IndexedColors.ORANGE.getIndex());
style.setFillPattern(CellStyle.SOLID_FOREGROUND);
cell = row.createCell((short) 2);
cell.setCellValue("X");
cell.setCellStyle(style);

// === Setting Background Pattern ===

//Accessing cell from the worksheet
Cell cell = cells.get("B2");
Style style = cell.getStyle();

//Setting the foreground color to yellow
style.setBackgroundColor(Color.getYellow());

//Setting the background pattern to vertical stripe
style.setPattern(BackgroundType.VERTICAL_STRIPE);

//Saving the modified style to the "A1" cell.
cell.setStyle(style);

// === Setting Foreground ===

//Adding custom color to the palette at 55th index
Color color = Color.fromArgb(212,213,0);
workbook.changePalette(color,55);

//Accessing cell from the worksheet
cell = cells.get("B3");

//Adding some value to the cell
cell.setValue("Hello Aspose!");

//Setting the custom color to the font
style = cell.getStyle();
Font font = style.getFont();
font.setColor(color);

cell.setStyle(style);